Results (pl)

Salt Experiments

All experiments done in Poland

Jumping grains of salt

Prepare:

  • Plastic wrap (for example broken balloon)
  • Rubber
  • A small plastic bowl
  • A dipper
  • Salt (Coarse grain) or rice seeds

Procedure:

  1. Stretch a plastic wrap over a bowl and attach it with a rubber.
  2. Put salt grains or rice on the stretched wrap.
  3. Place the pot near the bowl and hit it with a wooden spoon.

What is going to happen?

The grains are going to jump.

Why?

Under the influence of the hit, the air starts to vibrate creating sound waves. You can hear a sound. The sound waves encounter the bowl and make the plastic wrap vibrate. The vibrations make the grains or seeds move and they start to spin in the air.

 


Where is the salt?

Prepare:

  • A tablespoon of salt
  • A tablespoon of white flour
  • Water
  • 2 bowls

Procedure:

  1. Pour some water to each of the bowls.
  2. Pour the salt to one of the bowls and flour to another.

What is going to happen?

The flour is going to collect in the bottom of the bowl, the salt is going to disappear, and it is going to be invisible.

Why?

The flour does not dissolve in water but it instead turns to lump and it will slowly settle toward the bottom of the bowl. Salt does dissolve in water.

 


The magic egg

Prepare:

  • A raw egg
  • A glass filled with some tap water
  • Kitchen salt

Procedure:

  1. Place an egg in the glass. It is going to sink.
  2. Add a lot of salt to water and stir.

What is going to happen?

The egg will float in the saltwater but sinks in the ordinary tap water.

Why?

The density of an egg is higher than of tap water and that is why the egg will sink. The saltwater is denser than the regular water and an egg – the egg will float. You might have been in brine (very salty water). You might already know that you are not going to sink, aren’t you?

 


Potatoes and salt

Prepare:

  • A potato
  • A knife
  • A wooden cutting board
  • A bowl with water
  • 3-4 teaspoons of salt

Procedure:

  1. Slice up a potato into small pieces.
  2. In one of the bowl add 3-4 tablespoons of salt, and stir it in until it dissolves.
  3. Place some pieces in each bowl.

What is going to happen?

After two or three hours, the salt water pieces of potatoes will become soft and rubbery. They lost water.

Why?

The potatoes change because of the effect of Osmosis. Water will move from an area of less salt to more salt (more water to less water), and so when the potato is placed in the salt water, all the water that is inside the potato moves out by osmosis. Thus, the potatoes become soft and flexible.

 


This is an example of students' works.

Salt Experiments

grafik · realisierung · hosting – Volker Siebert, Berlin 2013 – mediafactum.